Calcium effects and systemic exposure of vitamin D 3 analogues after topical treatment of active vitamin D 3 -containing ointments in rats

Two-way Road of Kidney and Hypercalcemia: A Narrative Review

Calcium homeostasis is regulated by the dyad of parathyroid hormone and calcitriol, whereas kidney, intestine, and bone are the primary target sites. Elevation of serum calcium levels and hypercalcemia are likely markers of pathological conditions, particularly malignancy and hyperparathyroidism. Similarly, several dysfunctions within the body can direct hypercalcemia. Furthermore, chemicals and drugs can also drive this condition. Owing to the significant role of the kidney in calcium homeostasis, renal abnormalities lead to hypercalcemia and increased calcium levels can have pathological effects on the kidney. This review is designed to highlight some of the commonly known causes of hypercalcemia and their effects on the kidney.

Evaluating calcipotriene 0.005% foam for the treatment of plaque psoriasis of the scalp and body in patients aged 12 years and older

Introduction: Topical corticosteroids are the mainstay of treatment for mild-to-moderate psoriasis in adult and adolescent patients but there can be many adverse events associated with long-term corticosteroid use. Corticosteroid-sparing alternatives include Vitamin D3 analogs, such as calcipotriene (also known as calcipotriol), which have long been used as monotherapy or combination therapy with other topical agents to treat psoriasis. Calcipotriene's mechanism of action is not fully understood but it is believed to be effective due to its anti-proliferative and anti-inflammatory properties.Areas covered: Herein, the authors review the safety and efficacy of calcipotriene 0.005% aerosol foam, as well as factors affecting patient adherence to topical therapies. The authors offer an expert opinion and future perspectives on the use of calcipotriene foam as monotherapy compared with other topical pharmacotherapies.Expert opinion: Calcipotriene 0.005% foam is a safe and effective topical treatment when used to treat plaque psoriasis in patients aged 12 years and older. Despite its safety and efficacy, it remains largely utilized as a second-line agent due to its slow clinical improvement. Slow onset of action can result in poor patient adherence.

Sensitive and rapid UHPLC-MS/MS assay for simultaneous quantifications of calcipotriol and paclitaxel in rat whole blood and plasma samples

Vitamin-D analogues have emerged as potential stroma-modulating agents for the treatment of pancreatic ductal adenocarcinoma (PDAC). One such agent, calcipotriol (Cal) has shown significant activity in in vitro and in vivo models of pancreatic ductal adenocarcinoma. Attempts in our lab have been focused on establishing the therapeutic merits of co-formulating this agent with the chemotherapeutic drug paclitaxel (PTX) in animal models. Accurate and reliable quantifications of these agents is critical to successful pharmacokinetic/pharmacodynamic (PK/PD) projections from animals into humans. Herein, we developed a LC-MS/MS assay for measuring Cal and PTX in whole blood and plasma. A liquid-liquid analyte extraction procedure, using a mixture of water-MeOH (50:50, v/v) and hexane-dichloromethane- isopropyl alcohol (150:15:5, v/v/v) was used. Chromatographic separation was carried out on Kinetex C18 column (1.7 μm, 100 × 2.10 mm) under an isocratic elution at a flow rate of 0.4 mL/min with a total runtime of 3.5 min. The mobile phase was composed of ammonium acetate (pH 6.51; 5 mM)-methanol (15:85, v/v). The analytes were ionized by positive electrospray ionization using API 5500-Qtrap triple quadrupole mass spectrometer (Applied Biosystem/AB SCIEX). The linearity of calibration curves for both analytes were established at 0.5 (LLOQ)-500 ng/mL with correlation coefficients exceeding 0.99. Spiked whole blood and plasma samples were used as surrogates for matrix validation. For both analytes, the intra-day and inter-day accuracies were 90.5-105 % and 96.6-106 %, respectively, while the corresponding precisions were 3.09-10.7 % and 5.20-12.9 %. No carryover was observed for the analytes which also remained acceptably stable in the surrogate matrices under relevant conditions. The assay is robust, reliable and sensitive in rat whole blood and plasma. The analytes extraction procedure performs acceptably well in both matrices with high recoveries and minimal matrix effects. Additionally, only 20 μL of rat whole blood or plasma is required and the total run time per sample is 3.5 min. PK studies enabled by the assay revealed that when co-administered, PTX AUC_0→∞ and C_max increased while those of Cal decreased. This finding alerts a potential drug-drug interaction and warrants further investigation in studies using this combination regimen.

Pharmacokinetics of intra-articular vitamin D analogue calcipotriol in sheep and metabolism in human synovial and mesenchymal stromal cells

Calcipotriol (MC903) is a side chain analogue of the biologically active 1,25-dihydroxyvitamin D₃ [1,25(OH)₂D₃]. Due to its anti-inflammatory and anti-proliferative effects on stromal cells, calcipotriol is a promising candidate for the local treatment of arthritis. In this preliminary work, we studied the pharmacokinetics and safety of calcipotriol after an IV (0.1 mg/kg given to one sheep) and intra-articular dose (0.054 mg/kg, 0.216 mg/kg and 0.560 mg/kg given to three sheep). The terminal half-life of calcipotriol was approximately 1 h after an IV dose. After intra-articular dosing, the systemic absorption was between 1 and 13% during the observed 24 h. Hypercalcemia or other clinical adverse effects did not occur in any animal during the study, and no macroscopic or microscopic alterations were seen in the synovium of the calcipotriol-injected knees compared to the vehicle knees. The in vitro metabolism of calcipotriol was analyzed with LC-MS from human synovial and mesenchymal stromal cell cultures. Both cell types were able to metabolize calcipotriol with MC1080 and MC1046 as the main metabolites. CYP24A1 transcripts were strongly induced by a 48-hour calcipotriol exposure in mesenchymal stromal cells, but not consistently in synovial stromal cells, as determined by RT-qPCR. Calcipotriol proved to be safe after a single intra-articular dose with applied concentrations, and it is metabolized by the cells of the joint. Slow dissolution of calcipotriol crystals in the joint can extend the pharmaceutical impact on the synovium, cartilage and subcortical bone.

The burgeoning role of cytochrome P450-mediated vitamin D metabolites against colorectal cancer

The metabolites of vitamin D₃ (VD3) mediated by different cytochrome P450 (CYP) enzymes, play fundamental roles in many physiological processes in relation to human health. These metabolites regulate a variety of cellular signal pathways through the direct binding of activated vitamin D receptor/retinoic X receptor (VDR/RXR) heterodimeric complex to specific DNA sequences. Thus, the polymorphisms of VDR and VD3 metabolizing enzymes lead to differentiated efficiency of VD3 and further affect serum VD3 levels. Moreover, VDR activation is demonstrated to inhibit the growth of various cancers, including colorectal cancer. However, excessive intake of vitamin D may lead to hypercalcemia, which limits the application of vitamin D tremendously. In this review, we have summarized the advances in VD3 research, especially the metabolism map of VD3 and the molecular mechanisms of inhibiting growth and inducing differentiation in colorectal cancer mediated by VDR-associated cellular signal pathways. The relationship between VDR polymorphism and the risk of colorectal cancer is also illustrated. In particular, novel pathways of the activation of VD3 started by CYP11A1 and CYP3A4 are highlighted, which produce several noncalcemic and antiproliferative metabolites. At last, the hypothesis is put forward that further research of CYP-mediated VD3 metabolites may develop therapeutic agents for colorectal cancer without resulting in hypercalcemia.

Low systemic exposure and calcemic effect of calcipotriol/betamethasone ointment in rats with imiquimod-induced psoriasis-like dermatitis

Vitamin D₃ (VD₃) analogues-containing ointments are known to occasionally cause hypercalcemia in psoriasis patients, and the frequency of hypercalcemia is suggested to vary based on the VD₃ analogue used. In this study, to address the differences in calcemic effects of VD₃-containing ointments, the calcemic effects of marketed VD₃-containing ointments, including calcipotriol (Cal), maxacalcitol (Max), tacalcitol (Tac), calcipotriol/betamethasone dipropionate (Cal/BDP) and maxacalcitol/betamethasone butyrate propionate (Max/BBP) ointments, were evaluated in a rat model of imiquimod-induced dermatitis. The topical application of Tac, Max and Max/BBP ointments, but not Cal and Cal/BDP ointments, to the imiquimod-induced skin lesions significantly induced an increase in the serum calcium level compared with the vaseline-treated group. Calcemic effect of VD₃ analogues in rats treated with VD₃-containing ointments was analyzed by evaluating the expression of vitamin D receptor target genes, such as Cyp24a1, Trpv5 and CalbindinD28k, in the intestine and kidney. Real-time reverse transcription PCR (RT-PCR) analysis showed that the renal and intestinal Cyp24a1 expressions in the Cal- and Cal/BDP-treated groups were significantly lower than those in the Tac-, Max- and Max/BBP-treated groups, suggesting that systemic exposure of VD₃ analogues in the Cal- and Cal/BDP-treated groups were lower than those in the other ointment-treated groups. In addition, the renal Trpv5 and CalbindinD28k expressions, calcium-transporting genes, were increased in the Max- and Max/BBP-treated groups compared with the Cal- and Cal/BDP-treated groups. Thus, because of the low systemic exposure of VD₃ analogues, Cal and Cal/BDP ointments have lower calcemic effect than the other VD₃-containing ointments in rats with psoriasis-like dermatitis.